I. Field of the Invention
The present invention relates generally to turbochargers and, more particularly, to a turbocharger with a preloaded bearing assembly.
II. Description of the Prior Art
There are a number of previously known turbochargers having a housing in which a shaft is rotatably mounted. A turbine is attached to one end of the shaft and a compressor is attached to the opposite end of the shaft. Bearing assemblies, such as one or more ball bearing assemblies, rotatably mount the shaft to the housing.
In operation, the output from the compressor is connected to the intake of an internal combustion engine while the exhaust from the engine is connected to the inlet of the turbine. Thus, during operation of the engine, exhaust products from the engine rotatably drive the turbine which, in turn, drives the compressor which inducts fresh air, compresses the air and supplies the compressed air to the engine.
For effective operation of the turbocharger, the turbocharger shaft, and thus the turbine and the compressor, necessarily rotate at high rotational speeds. As a result, any vibration or play in the bearing assembly not only creates excessive noise but also results in rapid deterioration of the bearing assembly and its associated components.
There have, however, been a number of previously known devices which impose a load on the bearing assemblies in order to minimize any mechanical play within the bearing assemblies. These previously known devices, however, have been complicated and complex in construction and not wholly effective in operation. Furthermore, many of these previously known devices which preload the bearing assemblies impose uneven loads on the bearing assemblies which results in uneven wear.